First timer question about grading. 0

[dfaulkner]

Hi, just received my graded magic card from CGC, very fast turn around and it looks great in the mount! I do have a question about the "big number". Do you use a weighted average to arrive at the main grading number? If I do a straight average of the subs on my card: 10,9,8.5,8.5 = 36 / 4 is 9. The card is graded at 8.5. I'm happy that's it a 8.5, just curious about the process. 
Thanks
 

[Sambuck2]

I'm not sure the exact equation they use, but from what I've seen, it's rare to get more than a point higher for your overall grade than your lowest sub grade. For example you could have 10 centering, 9 edges, 8 corners and 3 surface and your card will grade 4 at best. So I assume to get a full point above your total grade it has to be a significant difference. But I don't know what that difference is.

[steveinthecity]

I'm not certain how individual subgrades are weighted, but if the two lowest subgrades match, that would be your final grade.  So 8.5 rather than a straight average as per your card.
 

[Jolthammer1]

Yeah, you can't do straight averages.  If you had a card that was in horrible shape, with corners = 1, surface = 1, edges = 1, and centering = 10.  You certainly aren't going to give that card an overall grade of a 3.